(Joy of Cooking)
1 cup + 2 Tbsp butter
2 cups packed brown sugar
2 eggs
2 tsp + 1 tsp vanilla
2 1/2 cups all-purpose flour
1 tsp baking soda
1 tsp table salt
3 cups rolled oats
2 cups (12 oz.) semisweet chocolate pieces
1 can (14 oz.) sweetened condensed milk
1/4 tsp salt
1 cup chopped walnuts or pecans (optional)
Heat the oven to 350. Cream 1 cup butter and brown sugar. Beat in eggs and 2 teaspoons vanilla. In another bowl, sift flour, baking soda, and salt and stir in rolled oats.
Over low heat, combine chocolate pieces, condensed milk, 2 tablespoons butter, and salt. Stir chocolate mixture until smooth, then add nuts and 1 teaspoon vanilla.
Combine egg and flour mixtures and press about two-thirds of it into a 10″ x 15″ jelly roll pan. Pour chocolate mixture over the batter, then dot the top with the remaining batter. Bake for about 25 minutes. When cool, cut into 1″ x 2″ bars.